Method and apparatus for treating sheet-like material with fluid

ABSTRACT

In air-through dryers for wet sheet-like material, such as paper, textiles, etc., the moist sheet-like material is subjected to an air pressure differential across the same so that heated or unheated air is caused to be engaged against one side of the sheet-like material and pass therethrough to the other side thereof to remove moisture from such sheet-like material as the air passes therethrough, such moisture being removed by a pushing out of the moisture by the air and/or by air entrainment. A belt means of this invention comprising a perforated flexible wall carrying felt fabric or other similar material on one side thereof is utilized in a manner to engage against the moist sheet-like material to compress the same during the passage of air through the perforated flexible wall and through the moist sheet-like material to assist in the water removal thereof by tending to cause the retained moisture of the sheet-like material to continuously fill the voids thereof and be more readily swept away by the air flow than when no compressing of the moist sheetlike material takes place.

United States Patent Candor et al.

[72] Inventors: Robert R.Candor, 5940 Munger Road, Dayton, Ohio 45459; James T. Candor, 5440 Cynthia Lane, Dayton, Ohio 45429 [22] Filed: Jan. 12, 1971 [21] Appl. No.: 105,894

[52] US. Cl. ..34/9 [51] Int. Cl F26b 3/00 [58 Field of Search ..34/9, 111, 115, 116, 123

[56] References Cited UNITED STATES PATENTS 2,888,378 5/1969 Maguire ...162/210 Primary Examiner-John J. Camby Attorney-Candor, Candor & Tassone BYAYIAY 1 Oct. 24, 1972 [57 ABSTRACT In air-through dryers for wet sheet-like material, such as paper, textiles, etc., the moist sheet-like material is subjected to an air pressure differential across the same so that heated or unheated. air is caused to be engaged against one side of the sheet-like material and pass therethrough to the other side thereof to remove moisture from such sheet-like material as the air passes therethrough, such moisture being removed by a pushing out of the moisture by the air and/or by air entrainment. A belt means of this invention comprising a perforated flexible wall carrying felt fabric or other similar material on one side thereof is utilized in a manner to engage against the moist sheet-like material to compress the same during the passageof air throughthe perforated flexible wall and through the moist sheet-like material to assist in the water removal thereof by tending to cause the retained moisture of the sheet-like material to continuously fill the voids thereof and be more readily swept away by the air flow than when no compressing of the moist sheet-like material takes place.

20 Claims, 7 Drawing Figures PATENTEDUBT 24 I972 'zv vav vi INVENTORS ROBERT R. CANDOR JAMES T. CANDOR BY W, gain F THEIR ATTORNEYS METHOD AND APPARATUS FOR TREATING SHEET-LIKE MATERIAL WITH FLUID This application is related to applicants copending application, Ser. No. 886,090, filed Dec. 18, 1969, and entitled METHOD AND APPARATUS FOR TREATING SHEET-LIKE MATERIAL WITH POROUS AND/OR PERMEABLE SHEET MEANS, and is related to applicants copending application entitled METHOD AND APPARATUS FOR TREAT- ING SHEET-LIKE MATERIAL AND THE LIKE, filed Oct. 20, 1969, Ser. No. 868,396, now US. Pat. No. 3,592,585, which is a continuation-in-part application of its copending patent application, Ser. No. 690,636, filed Dec. 14, 1967, now US Pat. No. 3,491,386, which, in turn, is a continuation-in-part'application of its copending patent application, Ser. No. 635,848, filed May 3, 1967, now US. Pat. No. 3,447,174.

This invention relates to means for improving the fluid treating of sheet-like material wherein the fluid is caused to'pass through the sheet-like material to treat the same, such as to remove moisture therefrom during a drying operation on the sheet-like material.

One of the features of the aforementioned patent applications is to provide a squeezing action on the material to be treated at the same time that gaseous fluid is being passed through the material to remove retained moisture thereof, the compressing or squeezing action being provided by means creating a pressure differential across a flexible nozzle means that engages against the material and has opening means through which the fluid flow takes place.

One feature of the present invention is to provide improvements in known air-through dryers of paper making apparatus by utilizing the aforementioned compressing features of applicants prior applications.

In particular, one embodiment of this invention provides a belt means which has a perforated flexible wall on one side thereof and a relatively open fabric covering on the other side thereof so that the fabric side of the belt means can engage against one side of the paper web that is to be dried whereby a pressure differential created across such belt means will cause the belt means to compress the paper web against a backing structure and will cause an air flow to pass through the perforations of the belt means, through the paper web and through the backing means to not only remove moisture from the paper web in substantially sheet form, but to also thereafter entrain water particles therefrom in a manner well known in the art and/or cause evaporation of the remaining moisture in a manner well known in the art. In this manner, the belt means of this invention provides the same function as the nozzle means of the aforementioned patent applications.

Further, it will be seen that another of the features of this invention is to provide a means for increasing the amount of time that the air flow through a moist paper web or the like is being utilized to strip moisture therefrom as bulk moisture rather than through just an entrainment process which normally occurs after the web by filling the previously emptied voids thereof so as to be readily stripped therefrom by the high air flow passing therethrough.

Accordingly, it is an object of this invention to provide an improved apparatus having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved method having one or more of the novel features set forth above or hereinafter shown or described.

Other objects, uses and advantages of this invention will be apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. 1 is a fragmentary, cross-sectional view illustrating one prior known air-through dryer utilizing the features of this invention.

FIG. 2 is a view similar to FIG. 1 illustrating another type of prior known air-through dryer utilizing the features of this invention.

FIG. 3 is a view similar to FIG. 1 and illustrates another prior known air-through dryer utilizing the features of this invention.

FIG. 4 is an enlarged, fragmentary cross-sectional view taken on line 44 of FIG. -1. v

FIG. 5 is an enlarged, fragmentary cross-sectional view taken on line 55 of FIG. 1.

FIG. 6 is an enlarged, fragmentary cross-sectional view taken on line 66 of FIG. 1.

FIG. 7 is a fragmentary, bottom perspective view of the roll means of the apparatus of FIG. 1 illustrating one means of this invention for maintaining the side edges of the belt means of this invention in contact with the peripheral edges of the roll of the apparatus of FIG. 1 and/or FIG. 2.

While the various features of this invention are hereinafter described and illustrated as being particularly adapted to remove moisture from paper webs as the same are being formed in conventional paper making apparatus, it is tobe understood that the various features of this invention can be utilized singly or in any combination thereof to provide means for treating other materials, such as textiles, food. products, etc., as desired.

Further, while this invention is described in connection with only one dryer drum for each type of paper making machine, it is to be understood that the belt means of this invention could be utilized with one or more air-through dryer drums for any one paper making apparatus, as desired. 1

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrated some of the wide variety of uses of this invention.

Further, while the embodiments of this invention are illustrated in the drawings as providing arcuate paths of travel for the sheet means being treated by the air flow, it is to be understood that such sheet means can be passed in a substantially straight line manner through the apparatus as set forth in certain of the aforementioned patent applications.

Referring now to FIG. 1, an air-through drying apparatus is generally indicated by the reference numeral 10 and comprises an air-through drying apparatus as set forth in FIG. 1 of the US. Pat. to Holden, No.

3 3,284,285, that is modified by a belt means 11 of this invention in a manner hereinafter described, the airthrough dryer of FIG. 1 will be hereinafter referred to as the Holden dryer and reference is hereby made to such Holden patent for particular details of the struc- In FIG. 2, another air-through dryer is generally indicated by the reference numeral 12 and is of the type disclosed in FIG. 1 of the U.S. Pat. to Sisson, No. 3,303,576, that is modified by the improved belt means 11 of this invention in a manner hereinafter described, the air-through dryer 12 of FIG. 2 being hereinafter referred to as the Sisson dryer and reference is hereby made to such Sisson patent for particular details of the structure, theory and operation of the Sisson dryer that are not hereinafter set forth.

Referring now to FIG. 3, another air-through dryer is generally indicated by the reference numeral 14 and is of the type set forth in FIG. 5 of the US. Pat. to Daane, No. 3,447,247, that is also modified by the belt means 11 of this invention in a manner hereinafter described, the air-through dryer 14 of FIG. 3 being hereinafter referred to as the Daane dryer and reference is hereby made to such Daane patent for particular details of the structure, theory and operation of the Daane dryer that are not hereinafter set forth.

The improved belt means 11 of this invention that is utilized in the Holden dryer 10, the Sisson dryer 12 and the Daane dryer 14 is best illustrated in FIG. 4 and comprises a flexible, perforated sheet 15 having a plurality of openings 16 passing therethrough in any suitable manner to produce a desired compressing and air flow effect that will be apparent hereinafter, the flexible sheet 15 having opposed sides 17 and 18 and carrying a compressible or non-compressible, relatively open fabric or felt band or covering 19 on the side 18 thereof with the band 19 providing an outer flat surface 20 for engaging against the desired material to be dried by the particular apparatus 10, 12 or 14 as will be apparent hereinafter. The openness and fiber structure of the covering band 19 can be so selected that the same will not have a tendency to mark or crush a paper web to be dried by the belt means 11, at least not to an adverse degree.

The'openings 16 through the flexible wall 15 of the belt means 11 of this invention are so selected that the same will permit air or other fluids to pass therethrough in such a manner that the fluid passing through the openings 16 and, through the covering 19 to the outer surface 20 thereof will be somewhat disfused by the covering 19 so that while jet-like fluid flow is passing through the belt means 11 as will be apparent hereinafter, such jet-like air means is substantially uniform and completely covering and flowing out of the outer surface 20 thereof in a manner somewhat produced by the jet patterns 21 schematically illustrated in FIG. 6 and hereinafter more fully described. Of course, the openings 16 can be formed in any manner to enhance the jet action of the fluid passing therethrough. For example, the openings 16 can be substantially frusto-conically shaped in the manner illustrated in FIG. 6. Of course, the openings 16 passing through the flexible wall 15 may be in slot form, or other configurations, if desired.

In any event, one of the features of the openings 16 of the flexible wall 15 of the belt means 11 is to permit a suitable fluid pressure to build up on the side 17 thereof so as to cause the flexible wall 15 to be moved in adirection away from the pressure build up on the side 17 thereof while still permitting fluid flow through the openings 16 thereof in high velocity jets as will be apparent hereinafter.

The Holden air-through dryer 10 of FIG. 1 comprises a rotatable cylinder or roll 22 rotatably mounted on a hollow shaft '23 and having a hollow interior 24 fluidly interconnected to the exterior peripheral surface 25 thereof by a plurality of openings 26 passing therethrough, the openings 26 being substantially nonrestrictive to fluid flow therethrough. The interior 24 of the cylinder 22 is divided into a pressure chamber 27 by stationary baffle means 28 carried by the shaft 32 that have sealing ends 29 for sealing engagement with the interior peripheral surface 30 of the roll 22 in the manner fully set forth in the aforementioned patent to Holden.

A fabric, felt or foraminous support means or belt 31 is adapted to carry a moist paper web 32 thereon and convey the same through a first nip defined by the cylinder 22 and a roller 33 with the paper 32 facing the exterior surface 25 of the cylinder 22, around part of the cylinder 22 and through another nip created by a roller ,34 cooperating with the cylinder 22, the paper sheet 32 and carrier 31 moving in unison from left to right in FIG. 1 whereby the paper sheet 32 would be held directly against the exterior surface 25 of the drum 22 adjacent the chamber 27 of the drum 22 if the belt means 11 of this invention were not utilized. If desired, a suitable chamber defining housing 35 can be disposed adjacent the roll 22 so as to define a chamber 36 on the other side of the chamber 27 of the roll 22, the chamber 36 being adapted to be interconnected to a vent or suction pump (not shown) by a conduit means 37.

The chamber 27 of the roll 22 is adapted to be pressurized by a suitable air pressure source (not shown) leading to the chamber 27 through the axially disposed hollow shaft 23 that has an outlet 38 in the manner fully set forth in the patent to Holden et al.

The belt means 11 of this invention is adapted to be fed between the paper sheet 32 and the outside surface 25 of the drum 22 at the roller means 33 and be separated therefrom at the roller means 34 as illustrated in FIG. 1 while passing around suitable guide rollers 39 and 40 leading respectively to and away from the drum 22 as illustrated with the band or covering 19 of the belt means 11 facing toward the paper sheet 32 so as to engage against the paper sheet 32 and move in unison therewith about the roll 22 between the rollers 33 and 34.

Without the belt means 11 of this invention, the aforementioned patent to Holden teaches that pressurized air in the chamber 27 of the roll 22 is forced out of the openings 26 of the roll 22 directly into the paper sheet 32 and through the paper sheet 32 and foraminous carrier 31 into the chamber 36 of the housing means 35 to be exhausted out of the conduit means 37 thereof as the paper sheet 32 and carrier 31 pass about the roll 22, such air flow through the paper sheet 32 first stripping the moisture therefrom in sheet form and thereafter removing additional moisture by the air entrainment thereof in the air flowing through the paper sheet 32 in the manner previously described.

The patent to Holden teaches that the carrier 31 can be utilized to compress the paper web against the surface 25 of the roll 22 by placing the carrier 31 under tension between the rollers 33 and 34, the squeezing purpose of the carrier 31' being to reduce theyvoid volume of the sheet 32 so that more water therefrom can be swept directly away by the air flow therethrough rather than by entrainment as would be the case when the sheet 32 is not compressed against the roll 22.

In particular, the patent to Holdenstates in column 1, lines 39-60 the following:

The present invention is directed particularly to removal of water from a paper web by establishing in the web one or more, streams of air or other gas which will flow generally vertically through the thickness of the web to dislodge water from the web. This is accomplished by exposing a substantial area of one surface of the web to a body of gas at superatmospheric pressure while the opposite surface of the web is supported on a porous member such as a screen or felt having gas: and water-permeable openings therethrough into which the gas and dislodged water may flow toward a zone of lower gaseous pressure. The body of pressurized air or gas will squeeze the web against the porous member and this may be supplemented by mechanical squeezing if so desired. Such squeezing with consequent reduction in thickness and void volume of the web will cause an increase in proportion of volume of water to total volume of the web. If the water in the web is subdivided it will tend to form into larger subdivisions which will be more readily dislodged by the gas. In many cases the water will form a continuous body which will be literally stripped from the web by the gas flowing therethrough.

.The patent to Sisson states that one of the problems in air-through dryers is that the air flow through the paper web is not uniform across the width of the moist paper web, the patent to Sisson stating in column 1, lines 54-71 and column 2, lines l-l2 the following:

While equipment such as that described above may be perfectly satisfactory in connection with low speed drying or where control of uniformity of moisture removal is not important, it has been found unsatisfactory when applied to the drying of lightweight porous paper webs at high rates of speed, for example, up to about 2,000 feet per minute, utilizing a practical range of roll diameters. The principal problem in connection with drying by means of the prior art devices described above is that the same invariably promote non-uniform drying across the width of the web being dried due to the fact that the flow pattern of the drying air varies greatly from side to side. While the adverse effects of this problem could be minimized in low speed drying by using cooler air, high speed dryers must, of necessity, use air having a temperature as high as possible consonant with the ability of the web material to. withstand heat at the moisture levels contemplated. Thus, if the dryer is designed to dry a paper web to an 80 percent consistency (0.25 pound of water per pound of fiber) the heated air can have a temperature at least as high as 700 F whereas if the web is to be brought to bone dry condition, the temperature of the air used should not exceed about 450 F. to avoid damaging the web fibers. If a high speed dryer is to reduce the level of moisture in a web to an 80 percent consistency and one edge of the web should dry substantially faster than the other edge or the center thereof, it is likely that the high temperature air used would severely damage the fibers in the areas which are prematurely dried while the balance of the web is brought to the moisture level contemplated.

The patent to Daane also describes the non-uniform air flow through the paper web as being a problem of air-through dryers, the patent to Daane stating in column 1, lines 63-71 and column 2, lines 1-32 the following:

In either of the foregoing types of dryers, which can be designated respectively as linear dryers and drum dryers, the rate at which moisture is removed from any given area of the web by air of a predetermined temperature and humidity is related to the weight and volume of air passing through that web area. Therefore,

if the entire area of the web positioned between the the flow of air through the web likewise will be substantially uniform, thereby resulting in correspondingly uniform drying. In actual practice, however, the porosity of the web is not entirely uniform, either due to local variations in fiber content or distribution, or, more importantly, due to variations in the amount of water entrapped among the fibers of the web. Hence, since an area of the web having less entrained water than surrounding areas is more permeable to air, a disproportionate volume of air passes preferentially through such an area of the. web, thereby accelerating further the drying of that particular area and continuously increasing the diversion of the available drying air from the relatively wetter surrounding areas.

As previously mentioned, the effectiveness of a dryer system of this general type is attributablein part to evaporation effected throughout the web by contact between the moist web fibers and the drying air; and also to entrainment and pushing of liquid moisture by the moving air stream. The later factor is particularly significant during the initial web drying operation, in which the web enters the dryer in a very wet condition, and can be visualized in terms of air pressure pushing water out of water-filled spaces between the web fibers and in terms of forcing air through the web with sufficient velocity to literally blow water out from among the web fibers as a result of the momentum of the rapidly moving air stream. While the amount of drying effected by evaporation is related rather directly to the weight and volume of air of a given temperature and humidity conducted through the web, the effectiveness of the liquid entrainment phenomenon varies as a function of the velocity of the air flow.

However, it is believed that by utilizing the belt means 11 of this invention in the Holden air-through dryer 10, an improved moisture removable operation will be provided by overcoming the problems mentioned by Sisson and Daane. In particular as the air pressure in the chamber 27 pressures against the side 17 of the flexible sheet 15 of the belt means 11, the same causes the sheet 15 and covering 19 thereof to move outwardly and thereby compact and compress the paper sheet 32 against the carrier 31 while high velocity jets of air pass through the openings 16 in the flexible wall 15 and through the covering 19 so as to pass completely through the paper sheet 32 as provided by the arrow pattern 21 illustrated in FIG. 6 to remove moisture. from the sheet 32 and pass out through the carrier 31 in a manner believed to remove a greater quantity of moisture from the paper sheet 32 since the paper sheet 32 is being continuously compressed by the flexible wall 15 to cause the remaining moisture therein to flow into the voids and fill the, same so as to be swept therefrom by the jet air flow passing through the sheet 32 which would not be the case once the certain pores of the sheet 32 had been swept clean by the air. The flexible wall 15 causes the belt means 11 to conform to the contour of the paper web 32 so that any billowing thereof is taken up by the flexible wall 15. Also, the jets of air passing out of the openings 16 of the wall 15 produce their water sweeping action independentally of the action of the other jets in the manner described in the patent to Daane.

Further, it is believed that as the moisture is continuously being removed from the sheet 32 by the jets of air passing through the openings 16 of the belt means 1 l of this invention, so that the paper 32 becomes more porous, a greater pressure differential is caused to exist across the flexible wall 15 to cause the same to compress the paper sheet 32 against the backing 31 with a greater force to thereby tend to cause a greater filling of the pores with remaining moisture in the sheet 32 to be swept therefrom in a manner previously described. Accordingly, the belt means 11 progressively increases its squeezing or compressing action on the paper web 32 as the belt means 1 1, paper web 32 and backing web 31 pass from the roller 33 to the roller 34.

Thus, it can be seen that the belt means 11 of this invention is believed to enhance the air-through drying action of the Holden air-through dryer by causing a continuous and progressively increasing compression or squeezing of the paper sheet means 32 as the same passes from right to left through the apparatus 10 between the rollers 33 and 34 so as to increase the amount of time that the moisture in the sheet 32 is being swept therefrom as moisture particles so that less time is required to pass air through the sheet means to remove the remaining moisture strictly by an air entrainment action and/or evaporative action. The belt means 11 also uniformily compresses the paper web 32 across the entire width thereof since the flexible wall of the belt means conforms to the contours of the sheet 32 and, thus, any billowing thereof relative to the drum 22. The belt means 11 also sweeps moisture from the paper web 32 by a plurality of jets that are independent of each other so that uniform moisture removal is created across the entire width of the paper web 32.

In order to hold the side edges 40 and 41 of the belt means 11 of this invention in substantially sealing relation with the peripheral side edges 42 and 43 of the roll means 22 between the seals 29 of the baffle means 28 at the chamber 27 so that the pressurized air will not tend to flow out of the same at the sides 40 and 41 thereof, a plurality of rollers 44 can be disposed adjacent the roll 22 at the side edges 42 and 43 thereof to hold the side edges 40 and 41 of the belt means 11 in sealing relation thereagainst as the belt means 11 passes around the roller 22, the paper web 32 having its 8 side edges disposed inboard of the rollers 44 as illustrated by dotted lines in FIG. 7.

Of course, it is to be understood that the belt means 11 can also be directly fastened to and completely around the roll 22 at the side edges 41 and 43 thereof so that the same will perform in the same manner as previously described except that the same will be carried by the drum 22 and not pass around the guide rollers 39 and as illustrated. The Sisson air-through dryer 12 of FIG. 2 will now be described and such apparatus 12 comprises a roll having a hollow center 46 interconnected to the exterior surface 47 thereof by a plurality of openings 48 passing through the roll 45. A foraminous backing 31 is adapted to pass around the outside surface 45 of the roll 45 by being passed around suitable rollers 49, 50 and 51 as illustrated with the paper sheet 32 passing between the backing 31 and the roll 45 as illustrated so that air inside the chamber 46 in the roll 45 will pass out of the same and through the paper 32 and the backing 31 in somewhat the same manner as the Holden device 10 previously described except that the air under pressure for the interior 46 of the roll 45 is directed into the same from the exterior of the roll 45 by a nozzle means 52 located between the rollers 50 and 51 and receiving air from a suitable fan means 53 that passes the air through suitable heating means 54 to the nozzle means 52 and, thus, through the exterior of the roll 45 into the interior 46 thereof. A removable chamber defining means 55 is provided by the apparatus 12 to be disposed about the outside of the roll 45 and define a chamber 56 that is adapted to be evacuated by suitable fan or pump means 57 so that a resulting pressure differential between the chamber 56 and the interior 46 of the roll 45 will exist across the surface 47 of the drum 45 and cause the heated air in the interior 46 thereof to pass through the openings 48 and, thus, through the paper sheet 32 and backing 31 into the chamber 56 to be exhausted therefrom with such air flow removing moisture from the sheet 42 in somewhat the manner previously described in connection with the Holden device 10.

However, the belt means 11 of this invention is utilized in the Sisson device 12, the belt means 11 being fed by suitable roller means 39 against the outside surface of the paper 32 at the roller 50 so that the covering 19 of the belt means 11 faces the sheet 32 while the flexible wall 15 engages against the roll 45 and is carried about the same to the roller 51 where the belt means 11 flow directed away from the roll 45 and around the guide roller 40 in the manner previously described.

Thus, it can be seen that as the paper sheet 32 is fed around the roll 45, the same is being continuously compressed by the belt means 11 of this invention against the backing means 31 for the reasons previously set forth in connection with the Holden device 10 so as to progressively squeeze or compress the sheet 32 by the pressure differential being created across the flexible wall 15 in the manner previously described during the air flow through the paper sheet 32 so as to remove a greater quantity of moisture therefrom than when the belt means 1 1 of this invention is not being utilized.

The Daane air dryer 14 of FIG. 3 is substantially an air impingement device which directs jets of air out of opening means 58 of a stationary hood 59 toward a perforated roll or drum 60 having the interior 61 thereof evacuated by suitable pump means 62 so that as a paper sheet passes around the roller 60 adjacent the openings 58 of the hood 59, the impinging air will pass directly through the paper sheet and, thus, through the openings 63 of the roll 60 to be exhausted from the interior 61 thereof. The hood 59 includes an interior chamber 64 adapted to receive air under pressure from a pump or fan means 65 with such air being heated by suitable heater means 66 before passing into the interior 64 of the hood 59.

A fabric or foraminous carrier 31 carries the paper sheet 32 and is guided against the exterior surface 67 of the roll 60 by a guide roller 68 so that the fabric 31 engages against the exterior surface 67 of the roll 50 while the nozzle means 58 of the hood 59 directs the jets of air directly against the paper sheet 32 to strip moisture therefrom as the air passes through the paper sheet 32 and into the interior 61 of the drum 60, the paper sheet 32 and fabric carrier 31 being directed away from the roll 60 by guide roller means 69.

However, the belt means 11 of this invention is utilized in the Daane dryer 14, the belt means 11 being also fed around the drum 60 at the roller means 68 and then away from the drum 60 by the roller means 69 with the belt means 11 being fed toward the roller 68 by the roller means 39 and away from the roller means 69 by the roller means 40 in the manner previously described. In this manner, the covering side of the cover means 19 of the belt means 11 will engage against the paper sheet 32 as the same passes around the roll 60 and the jets of air from the opening 58 of the hood or cap 59 will engage against the flexible wall 15 and will cause the belt means 11 to continuously compress toward the paper sheet 32 and squeeze the same against the backing 31 on the roll 60 while issuing jets of air out of the openings 16 of the belt means 11 for moisture removal from the paper sheet 32 as the paper sheet 32 passes beneath the hood 59 in the manner previously described. If desired, the hood 59 can be substantially sealed to the moving flexible wall 15 of the belt means 11 as the same passes underneath the same by annular seal means 70 carried by the hood 59 in much the same manner as the seal means provided by the hood means of the air-through dryer of the U.S. Pat. to Villalobos, No. 3,541,697.

Thus, it can be seen that in the various types of airthrough dryers illustrated in FIGS. 1, 2 and 3, the belt means 11 of this invention is believed to improve the operation thereof because the belt means 11 causes the wet sheet to be continuously and progressively compressed or squeezed as the same passes through the airthrough dryer so that the moisture therein tends to continuously till all voids thereof and be more readily swept therefrom by the air flow therethrough than as would be the case if the air flow through the paper sheet is merely trying to remove the moisture therein by air entrainment rather than by sweeping the same ahead of the high velocity air flow passing therethrough.

While the form of the invention now preferred has been disclosed and described as required by the patent statutes, other forms may be utilized all coming within the scope of the claims which follow.

What is claimed is:

1. In an air-through drying apparatus for wet sheetlike material wherein moisture from the wet sheet-like material is removed therefrom by air flowing substantially transversely through the sheet-like material by a pressure differential being created across the sheet-like material as the same passes through said apparatus, the improvement comprising a belt means for engaging against said sheet-like material as the same passes through said apparatus and being disposed on the higher pressure side of said sheet-like material, said belt means having means forcausing the air flow'to compress said belt means against said sheet-like material while flowing through said belt means into said sheetlike material to remove moisture therefrom, said means of said belt means comprising opening means passing through said belt means, said belt means comprising a flexible wall having said opening means passing therethrough, said belt means having an air open covering on the side thereof that is to engage said sheet-like material and cover said opening means.

2. In an apparatus as set forth in claim 1, the further improvement wherein said apparatus has movable support means for conveying said sheet-like material through said apparatus, said belt means being disposed between said support means and said sheet-like material.

3. In an apparatus as set forth in claim 1, the further improvement wherein said apparatus has movable support means for conveying said sheet-like material through said apparatus, said belt means being disposed on the side of said sheet-like material that faces away from said support means.

4. In an air-through drying method for wet sheet-like material wherein moisture from the wet sheet-like material is removed therefrom by air flowing substantially transversely through the sheet-like material when the sheet-like material is passed through a pressure differential creating zone, the improvement comprising the steps of engaging a belt means against said sheetlike material on the higher pressure side of said sheetlike material in said zone so that the air flow in said zone will compress said belt means against said sheetlike material while flowing through said belt means into said sheet-like material to remove moisture therefrom, providing opening means through said belt means for the passage of said air therethrough, forming said belt means from a flexible wall having said opening means therethrough, and covering said flexible wall with an air open covering material that is to engage said sheet-like material and cover said opening means.

5. In a method as set forth in claim 4, the further improvement comprising the step of disposing said belt means between said sheet-like material and a movable support means that conveys said sheet-like material through said zone.

6. In a method as set forth in claim 4, the further improvement comprising the step of disposing said belt means on the side of said sheet-like material that faces away from a movable support means that conveys said sheet-like material through said zone.

7. In an air through drying apparatus of the high velocity air flow hood type for wet sheet-like material wherein moisture from the wet sheet-like material is removed therefrom by superatmospheric air flowing from said hood substantially transversely through the sheet-like material by a resulting pressure differential being created across the sheet-like material as the same passes through the hood of said apparatus, the improvement comprising a flexible wall means for engaging against said sheet-like material as the same passes through said hood of said apparatus and being disposed on the higher pressure side of said sheet-like material, said flexible wall means having means for causing the air flow to compress said flexible wall means against said sheet-like material while flowing through said flexible wall means into said sheet-like material to remove moisture therefrom.

. 8. In an apparatus as set forth in claim 7, the further improvement wherein said means of said flexible wall means comprises opening means passing through said flexible wall means.

9. In an apparatus as set forth in claim 8, the further improvement wherein said flexible wall means has a flexible wall having said opening means passing therethrough, said flexible wall means having an air open covering on the side of said flexible wall that is to engage said sheet-like material and covering said openin g means.

10. In an apparatus as set forth in claim 7, the further improvement wherein said apparatus has movable support means for conveying said sheet-like material through said hood of said apparatus, said flexible wall means being a continuous belt means disposed completely within said hood.

1 1. In an apparatus as set forth in claim 7, the further improvement wherein said apparatus has movable support means for conveying said sheet-like material through said apparatus, said flexible wall means being disposed on the side of said sheet-like material that faces away from said support means.

12. In an air-through drying method for wet sheetlike material wherein moisture from the wet sheet-like material is removed therefrom by superatmosheric air flowing from a high velocity air flow hood substantially transversely through the sheet-like material when the sheet-like material is passed through a resulting pressure differential creating zone defined in part by said high velocity air flow hood, the improvement comprising the step of engaging a flexible wall means against said sheet-like material on the higher pressure side of said sheet-like material as the same passes through said hood so that the air flow in said zone will compress said flexible wall means against said sheet-like material while flowing through said flexible wall means into said sheet-like material to remove moisture therefrom.

13. In a method as set forth in claim 12, the further improvement comprising the step of providing opening means through said flexible wall means for the passage of said air therethrough.

14. In a method as set forth in claim 13, the further improvement comprising the steps of forming said flexible wall means from a flexible wall having said opening means therethrough, and covering said flexible wall with an air open covering material that is to engage said sheet-like material and cover said opening means.

15. In a method as set forth in claim 12, the further improvement comprising the steps of forming said flexible wall means to form a continuous belt means, and disposing said belt means completely within said hood.

16. In a method as set forth in claim 12, the further improvement comprising the step of disposing said flexible wall means on the side of said sheet-like material that faces away from a movable support means that conveys said sheet-like material through said hood.

17. In a fluid-through apparatus for sheet-like material wherein the sheet-like material is treated by fluid flowing substantially transversely through the sheet-like material by a pressure differential being created across the sheet-like material as the same passes through said apparatus, the improvement comprising a belt means for engaging against said sheet-like material as the same passes through said apparatus and being disposed on the higher pressure side of said sheet-like material, said belt means having means for causing the fluid flow flow to compress said belt means against said sheet-like materialwhile flowing through said belt means into said sheet-like material to treat the same, said means of said belt means comprising opening means passing through said belt means,

said belt means comprising a flexible wall having said opening means passing therethrough, said belt means having a fluid open covering on the side thereof that is to engage said sheet-like material and cover said opening means.

18. In a fluid-through method for sheet-like material wherein the sheet-like material is treated by fluid flowing substantially transversely through the sheet-like material when the sheet-like material is passed through a pressure differential creating zone, the improvement comprising the steps of engaging a belt means against said sheet-like material on the higher pressure side of said sheet-like material in said zone so that the fluid flow in said zone will compress said belt means against said sheet-like material while flowing through said belt means into said sheet-like material to treat the same, providing opening means through said belt means for the passage of said fluid therethrough, forming said belt means from a flexible wall having said opening means therethrough, and covering said flexible wall with a fluid open covering material that is to engage said sheet-like material and cover said opening means.

19. In a fluid-through apparatus of the high velocity fluid flow type for sheet-like material wherein the sheet-like material is treated by pressurized fluid flowing from a chamber of said apparatus substantially transversely through the sheet-like material by a resulting pressure differential being created across the sheetlike material as the same passes through said apparatus, the improvement comprising a flexible wall means for engaging against said sheet-like material as the same passes through said apparatus and being disposed on the higher pressure side of said sheet-like material, said flexible wall means having means for causing the fluid flow to compress said flexible wall means against said sheet-like material while flowing through said flexible wall means into said sheet-like material to treat the same.

20. In a fluid-through method for sheet-like material wherein the sheet-like material is treated by pressurized fluid flowing from a high velocity fluid flow chamber substantially transversely through the sheetlike material when the sheet-like material is passed,

through a resulting pressure differential creating Zone defined in part by said high velocity fluid flow chamber, the improvement comprising the step of engaging a flexible wall means against said sheet-like material on Disclaimer 3,699,663.R0bert R. Gander and James T. Oandor, Dayton, Ohio. METHOD AND APPARATUS FOR TREATING SHEET-LIKE MATE- RIAL WITH FLUID. Patent dated. Oct. 24, 1972. Disclaimer filed Apr. 26, 197 2, by the inventors. Hereby disclaims the portion of the term of the patent subsequent to July 13,1988. 2

[Ofiiez'al Gazette September 11,1973] 

1. In an air-through drying apparatus for wet sheet-like material wherein moisture from the wet sheet-like material is removed therefrom by air flowing substantially transversely through the sheet-like material by a pressure differential being created across the sheet-like material as the same passes through said apparatus, the improvement comprising a belt means for engaging against said sheet-like material as the same passes through said apparatus and being disposed on the higher pressure side of said sheet-like material, said belt means having means for causing the air flow to compress said belt means against said sheet-like material while flowing through said belt means into said sheet-like material to remove moisture therefrom, said means of said belt means comprising opening means passing through said belt means, said belt means comprising a flexible wall having said opening means passing therethrough, said belt means having an air open covering on the side thereof that is to engage said sheet-like material and cover said opening means.
 2. In an apparatus as set forth in claim 1, the further improvement wherein said apparatus has movable support means for conveying said sheet-like material through said apparatus, said belt means being disposed between said support means and said sheet-like material.
 3. In an apparatus as set forth in claim 1, the further improvement wherein said apparatus has movable support means for conveying said sheet-like material through said apparatus, said belt means being disposed on the side of said sheet-like material that faces away from said support means.
 4. In an air-through drying method for wet sheet-like material wherein moisture from the wet sheet-like material is removed therefrom by air flowing substantially transversely through the sheet-like material when the sheet-like material is passed through a pressure differential creating zone, the improvement comprising the steps of engaging a belt means against said sheet-like material on the higher pressure side of said sheet-like material in said zone so that the air flow in said zone will compress said belt means against said sheet-like material while flowing through said belt means into said sheet-like material to remove moisture therefrom, providing opening means through said belt means for the passage of said air therethrough, forming said belt means from a flexible wall having said opening means therethrough, and covering said flexible wall with an air open covering material that is to engage said sheet-like material and cover said opening means.
 5. In a method as set forth in claim 4, the further improvement comprising the step of disposing said belt means between said sheet-like material and a movable support means that conveys said sheet-like material through said zone.
 6. In a method as set forth in claim 4, the further improvement comprising the step of disposing said belt means on the side of said sheet-like material that faces away from a movable support means that conveys said sheet-like material through said zone.
 7. In an air through drying apparatus of the high velocity air flow hood type for wet sheet-like material wherein moisture from the wet sheet-like material is removed therefrom by superatmospheric air flowing from said hood substantially transversely through the sheet-like material by a resulting pressure differential being created across the sheet-like material as the same passes through the hood of said apparatus, the improvement comprising a flexible wall means for engaging against said sheet-like material as the same passes through said hood of said apparatus and being disposed on the higher pressure side of said sheet-like material, said flexible wall means having means for causing the air flow to compress said flexible wall means against said sheet-like material while flowing through said flexible wall means into said sheet-like material to remove moiSture therefrom.
 8. In an apparatus as set forth in claim 7, the further improvement wherein said means of said flexible wall means comprises opening means passing through said flexible wall means.
 9. In an apparatus as set forth in claim 8, the further improvement wherein said flexible wall means has a flexible wall having said opening means passing therethrough, said flexible wall means having an air open covering on the side of said flexible wall that is to engage said sheet-like material and covering said opening means.
 10. In an apparatus as set forth in claim 7, the further improvement wherein said apparatus has movable support means for conveying said sheet-like material through said hood of said apparatus, said flexible wall means being a continuous belt means disposed completely within said hood.
 11. In an apparatus as set forth in claim 7, the further improvement wherein said apparatus has movable support means for conveying said sheet-like material through said apparatus, said flexible wall means being disposed on the side of said sheet-like material that faces away from said support means.
 12. In an air-through drying method for wet sheet-like material wherein moisture from the wet sheet-like material is removed therefrom by superatmosheric air flowing from a high velocity air flow hood substantially transversely through the sheet-like material when the sheet-like material is passed through a resulting pressure differential creating zone defined in part by said high velocity air flow hood, the improvement comprising the step of engaging a flexible wall means against said sheet-like material on the higher pressure side of said sheet-like material as the same passes through said hood so that the air flow in said zone will compress said flexible wall means against said sheet-like material while flowing through said flexible wall means into said sheet-like material to remove moisture therefrom.
 13. In a method as set forth in claim 12, the further improvement comprising the step of providing opening means through said flexible wall means for the passage of said air therethrough.
 14. In a method as set forth in claim 13, the further improvement comprising the steps of forming said flexible wall means from a flexible wall having said opening means therethrough, and covering said flexible wall with an air open covering material that is to engage said sheet-like material and cover said opening means.
 15. In a method as set forth in claim 12, the further improvement comprising the steps of forming said flexible wall means to form a continuous belt means, and disposing said belt means completely within said hood.
 16. In a method as set forth in claim 12, the further improvement comprising the step of disposing said flexible wall means on the side of said sheet-like material that faces away from a movable support means that conveys said sheet-like material through said hood.
 17. In a fluid-through apparatus for sheet-like material wherein the sheet-like material is treated by fluid flowing substantially transversely through the sheet-like material by a pressure differential being created across the sheet-like material as the same passes through said apparatus, the improvement comprising a belt means for engaging against said sheet-like material as the same passes through said apparatus and being disposed on the higher pressure side of said sheet-like material, said belt means having means for causing the fluid flow flow to compress said belt means against said sheet-like material while flowing through said belt means into said sheet-like material to treat the same, said means of said belt means comprising opening means passing through said belt means, said belt means comprising a flexible wall having said opening means passing therethrough, said belt means having a fluid open covering on the side thereof that is to engage said sheet-like material and cover said opening means.
 18. In a fluid-through method for sheet-like material Wherein the sheet-like material is treated by fluid flowing substantially transversely through the sheet-like material when the sheet-like material is passed through a pressure differential creating zone, the improvement comprising the steps of engaging a belt means against said sheet-like material on the higher pressure side of said sheet-like material in said zone so that the fluid flow in said zone will compress said belt means against said sheet-like material while flowing through said belt means into said sheet-like material to treat the same, providing opening means through said belt means for the passage of said fluid therethrough, forming said belt means from a flexible wall having said opening means therethrough, and covering said flexible wall with a fluid open covering material that is to engage said sheet-like material and cover said opening means.
 19. In a fluid-through apparatus of the high velocity fluid flow type for sheet-like material wherein the sheet-like material is treated by pressurized fluid flowing from a chamber of said apparatus substantially transversely through the sheet-like material by a resulting pressure differential being created across the sheet-like material as the same passes through said apparatus, the improvement comprising a flexible wall means for engaging against said sheet-like material as the same passes through said apparatus and being disposed on the higher pressure side of said sheet-like material, said flexible wall means having means for causing the fluid flow to compress said flexible wall means against said sheet-like material while flowing through said flexible wall means into said sheet-like material to treat the same.
 20. In a fluid-through method for sheet-like material wherein the sheet-like material is treated by pressurized fluid flowing from a high velocity fluid flow chamber substantially transversely through the sheet-like material when the sheet-like material is passed through a resulting pressure differential creating zone defined in part by said high velocity fluid flow chamber, the improvement comprising the step of engaging a flexible wall means against said sheet-like material on the higher pressure side of said sheet-like material as the same passes through said zone so that the fluid flow in said zone will compress said flexible wall means against said sheet-like material while flowing through said flexible wall means into said sheet-like material to treat the same. 